Method of and means for treating fluid hydrocarbons



April 2, 1929. F. B. FRETTER 1,707,606

METHOD OF AND MEANS FOR TREATNG FLUID HYDROCARBONS Filed June 3.8, 1925 2 Sheets-Shes*L l \g SUPPLY PIPE ,71- ro nwe Y April 2, 1929. B, FRETTER 1,707,606

METHOD OF AND MEANS FORl TREATTNG FLUID HYDROCARBONS Filed June 18, 1925 2 Sheets-SheetV 2 IN veA/row KB. FRETTEH.

Patented Apr. 2, 19,29.-A

UNITEn STATES A 1,707,606 PATENT OFFICE.

raam: n. narran. orcLEvELaND, omo, assIGNoR 'ro THE NATIONAL nml-mme conm,- or cLEvELANn, omo, a coaronarron or omo.

nunon or AND mms non eram'rme FLUID maocmoxs.

applicati@ mea :une 1s, 1925. serial No. 37,941.

My invention relates to 'improvements in method of and means :for treating iluld hydrocarbons, and has primaril lfor 1ts object the l economical treating of suc hydro-carbons to insure the rearrangement of molecules and produce what commonl is termed the art as cracking for obtaining a gasoline content. z

The procedure differs from any with which I have 'previously become acquainted by reason of the fact that the fluid hydro-carbon is maintained under an excessive pressure during the heating thereof, which pressure preferably is produced by a high-pressure pump,

acting against a small orifice, while the treated hydrocarbon is suddenly released from such pressure through an accelerating vent, such as a Venturi tube or outlet, whereby the cracking operation is materially augmented.

As a secondary object of my invention, I effect a recycling of the treated stock and conservation of heat, so that a maximum cracking eiect is obtained with attendant econom1es.

The process and apparatus suitable for practicing the same may best be explained in connection with the accompanying drawings, wherein: L

Figure 1 is a diagrammatic view, principally in vertical sections, lillustrating means for practicing the process or method of my invention.

Figure 2 is an enlarged view, in 'vertical section, of the adjustable discharge nozzle associated with the apparatus diagrammatically shown in Figure 1, and

Figure 3 is an end view of the said nozzle.

Throughout the several figures of the drawings, I have employed the same characters of reference to indicate similar parts.

Referring first to the diagram of Figure 1, there is shown, at the left of the drawing, a tube heater, a, having a gas burner, lb, and a chimney stack, c, all of the usual type. The terminal connectors, c', of the tubes, c, preferably maintain throughout, the heater an equal area for the free passage of the fluid hydro-carbone.

This heater, a, is supplied by a high pressure pump, d, to wit, one that will be capable of maintaining a pressure upward of onel amometer( i; one hundred an understood that my process is not dependant upon any particular gravity of hydro-carbon.`

Assuming that the tower, f, has been filled approximately one-eighth (1/8) of its height, as indicated, this level will be maintained and against the .suppl in said tower, the pump, d, will be starte filling the tubes ofthe heater with fluid hydro-carbon. The burner, b, is then ignited, and the needle valve, yIt', of the nozzle, h, is slightly opened to permit the continued flow of hydro-carbons while heatmg, and prevent the burning out of the tubes. Roughly, the pressure maintained by the pump, d, Will increase proportionately with the temperature as observed u on the thertwenty-five. pounds 125#), approximately, being maintained at degrees F.; five hundred unds (500#) approximately, being maintamed at 400 degrees F.; eight hundred and seventyive pounds (875 ),l approximatel bein maintained at 700idegrees F., and oie thoug- `sand pounds (1,000#) andu ward being back pressure device is essential, which may be embodied in a restricted orifice of any suitable character. In order to regulate the size of the orifice in accordance with different working conditions and /diiferent distillates, I preferably employ the nozzle, h, which is shown in Figures 2 and 3, although my invention does not necessarily depend upon the mechanical details therein shown, and which I will here describe.v

'This nozzle, h, embodies the features-of a velocity tube, comprising a gradually constricted neck, k", connecting with the needle valve seat, k2; the needle valve stem, h, loosely sliding in a s ider, h, and controlled at the opposite or le t hand end by a screw, h, and hand wheel, la, while a gland, h', is packed to resist the high pressures necessarily res being ap licable placedupon this appliance. It will be obn served w1th this construction, the-valve stem being of even diameter upon the enteringside of thevelocity tube, that an even flow may be accurately gured and maintained with a iven o ening of the needle valve, h. Un-

' er wor 'n conditions, the opening willap- 'proximate t ree-eighths ('78) of anmch aren,

'practically at atmospheric pressure.

A pipe of large diameter, jf', leads into the tower, f, beneath the beaming, f', and the 'y sa tous hydro-cdrbon will immediately exit through the tower, f, and homing,

f g'the heavier fractions thereof condensing at approximately '350 to 400 degrees F., and seeking the bottom of the tower, while those still invaporous condition would pass over through pipe, ff-f, tothe cooling distillate, which is condensed 1n la, comprises the crude benzine and may be 'treated in the usual manner `forobtaining its gasoline content'. 1

Turning nowwtoy a more detailed discussion of my process, and my understanding of the theory under Whichit operates, I may say that the treated hydro-carbon ismaintained in duid condition, b reason of the excessive ressure maintains by ump, oi', and is riven so rapidly through tie tubes, c, of the heater, o, t at no material deposit is left withinthe tubes, and no actual cracking takes fnozzle place, ,until the hydro-carbon is instantaneously freed from said pressure by being driven through .the adjusted orifice of the At least, an immediate separation occurs between the va crous hydro-carbons as introduced into t e vaporizr, j; the heavier constituents remaining in duid condition and being drawn oli from time to time through the valve, 5, while the gaseous hydro-carbons whichv have been partly cracked at this stage will dow through the tower, f, and be separated by the usual condensing action therein, as previously indicated.

It is obvious that the supply within the base of the tower, soon becomes heated by the condensing hydro-carbone from the beding, f', and from `this-heated supply, augmented by the newly supplied. hydrocar' y us, the ump, d, recycles the hydro-carbon for iurt er treatment in the tubes, as previously explained.

box, lc. This vA discharge valve, l, is provided in the line leading from the heater, a, if it is necessary,

"for any reason, to suspend the cracking operthe needle ation within the vaporizer, valve zl then being tightly c ose'd.. l

' Another f discharge valve, m, is provided for draining the accumulated hydro-carbons' from the base of the tower, f, in case of shutdown or repairs. p

l A high pressure gauge, n, is provided adjacent tothe pump, vLandv a vacuum and atmospheric pressure gauge, o, is provided upon the dome of the vaporizer, j; while liquid gauges, p and g, respectively, are associated with the vapor-12er, j, and the tower, f, but these and other details donotrequire description nor further illustration in explaining my invention to those skilled in the art. n

. One other detail, however, may be adverted to, comprising the discharge valve, r, as-

sociated with the tubes' of the heater. When it is necessary to discontinue o erations, the valve, 1", connected with a 1gb-.pressure steam luie, 1s opened -concurrently with the stoppage of pump, d, and the valve, Z, also is,

opened. This permits the coolin of tubes and their substantial discharge, a 'ter which the draw-ofi valve, 7', is opened to drain the remnant of oil and water therefrom.

Apparently the hydrocarbon within the heater tubes is in an imminent state of dissociation but-is maintained in initial fluid form b the excessive pressure applied thereto by t e pump. The velocity tube may conform to the lines of, or approximate a Venturi tube, in order that the discharge may be more rapid and e'ective within the vaporizer. As recycling proceeds, or a hydrocarbon oi'y higher specific gravity is emplo ed, the temperature may be advantageous y increased, say to 850 F., and upward, while the pressure will be regulated from time to time'in corres ondence with the instant working conditions, of which I have given an illustrative example: above. -In all cases, extreme care must be exercised to prevent the burning out of the pressure tubes within the heater.

It will be' seen that the separation of the heavier hydrocarbons is edected in this rocess immediately upon the discharge o the 'treated hydrocarbon into the va orizer under normal pressure, i. e., slightly a ove or below atmospheric pressure. This separation is preferable so as to avoid recycling those hydrocarbons which are substantially resistant to cracking operations.

In consideringthe a pended claims, the acceleration referred to tlierein at the moment of the discharge of the hydrocarbons, and the velocity tube for obtaining such acceleration and increase in the cracking reaction,relate to the known action of the Venturi tube and itsphysical` features, respectively and the clais are to be read with this de tion in l:los

ing fluid hydrocarbons, which consists of rapidly impelling the treated hydrocarbon through a heater u-nder extraneous pressure approximating 1000 poundsper square inch and obtain-in a working temperature for said hydrocar on in excess of 800 F., permitting the escape from the heater of graduated volumes of the hydrocarbon through an accelerating venthaving the characteristics of the Venturi tube intoa vaporizing chamber at approximatel atmospheric pressure, and separating the eavier and lighter hydro-v carbons resulting from this treatment, sub-y stantially as set forth.v

2. The herein described method of'treatingfluid hydrocarbons, which consists of pumping the treated hydrocarbon through a ,tube heater under pressure in excess of,v 13000' pounds per square' inch and a temperature upward of 850 F., at a rate to prevent ma,.-

I terial` deposit within the heater, unrestricted# ly accelerating the escape of the hydrocarbon fromY the heater into a vaporizing chamber, substantially at atmospheric'pressure as by Venturi tube action, whereby the released hydrocarbon is subjected to a crack'infr reaction and effecting the separation o? the heavier and lighter -hydrocarbons resulting from said treatment, substantially' as set forth.

3. The herein described method of treating ao luid'hydrocarbons, which consists of rapidly impelling the treated hydrocarbon through a heater. of restrictedl cross-sectional area under extraneous `working pressure a proximating.10007pounds per square inc `and at a mesne working tem rature of 800 F., more or less, unrestricted y accelerating the escape from the heater of graduated volumes of the hydrocarbon into a vaporizing chamber at nominal pressure as vby Venturi tube action, and separating the heavier and lighter hydrocarbons resulting from this treatment, sub-A stantially as set orth. 'i

4. vThe fluid h drocarbons, which consistsof rapid impelling .the treated hydrocarbon througi a heaterof restricted cross-sectional area unl der extraneous worln'ng pressure approximating 1000 pounds perzsquare Ainch and at a herein described method of treating v mesne Iworking.temperature ofv 850 F., more or less, unrestrictedlyf' accelerating the esca e from the heater of graduatedjvolumes of the l hydrocarbon into a vaporizing 'chamber at nominal pressure as, by. Venturi tube action, c

separating the heavier and. lighter hydrocarbons ',resultino' from this'trea-tment, and re-l 'cycling the distillate condensing at 400,, F.,

more or less, substantially as set forth.

5. In apparatusof the class described, a combined elbow and velocity tube for cracking chambers, comprising an elbow memberv tapered past the turn thereof to form a Ven-- turi-tube outlet, a valve member in the axis of said tube, a packing at the elbow, and screw-acting means for openin and closing the outlet, substantially as set orth.-

6. In apparatus of the class described, com,- prising a combined elbow ,and velocity tube for vaporizing chambers and the like, an el-g bow member having a relatively large-inlet atan angle with a tapered section forming a Venturi-tube outlet, a movable reversely tapered valvey rod positioned i'n the axis of said ltube, ar packing atthe elbow turn, and ex-. `terior screw-acting means for opening and closing 'the outlet and for regulating its openin or clearance, substantially as set forth.

d. Theherein described method of treating fluid hydrocarbons which consists of rapidly impelling the treated hydrocarbon through a uconstricted heater under extraneous pressure approximating 1000 pounds per square inch and obtaining a working temperature. for said hydrocarbons in excess of 800 F., erecting the accelerated esca e from the heater of graduated volumes o the hydrocarbon, as by Venturi action, into a vaporizing chamber approximately at atmospheric pressure, and separating the heavier and lighter hydrocarbons resulting from said treatment. 8. The herein describedmethod of treating fluid hydrocarbons, which consists of rapidl pumping the treatedhydrocarbons throug a heater of restricted' cross sectional area and extended length under extraneous working pressure approximating 1000, pounds per square inch "and atan approximate working temperatureof 850 F., more or less, eiecting the accelerated escape, as by Venturi action, of graduated volumes of the `hydrocarbons into a vaporizing chamber at nominal pres sure, an'd separating the heavier and lighter hydrocarbonsresulting from said treatment" l and accelerated discharge.

In testimony whereof I do now aix my sigf nature.

FRANK B. FRETTER.` 

